Chanterelles in the wild are shown in the picture above.
Mushrooms are apparently only vegetarian food that can actually make Vitamin D…. because they have “pro-vitamin,” or precursor, called ergosterol that converts into vitamin D when exposed to the sun’s ultraviolet (UV) radiation. It works in a similar way to how skin synthesizes the vitamin when it gets the right level of sun exposure. Before you all go get tempted to buy lots in read on as It’s important to know that shop bought ones are mostly commercially cultivated and nearly always grown indoors in the dark, which simply means their value of Vitamin D is negligible.
In contrast, the wild mushrooms you can foliage for such as chanterelles, maitake, and morels—are authentic and richer in Vitamin D because they get natural sun exposure and if left out longer will naturally come with a rich source of vitamin D.
Over the past decade, scientists have been studying mushrooms and the impact of VU rays. They have found that modest amount of UV from the natural sun or special VU lamps produce vitamin D in mushrooms and interestingly enough, 15 minutes of direct sunlight can produce 200 to 800 IU in 3 ounces of mushrooms (the RDA is set as 600 to 800 IU although you can have more), regardless of type or season and at least 90 percent of vitamin D is retained even after storage or when being cooked. The Whole button mushrooms have been researched to synthesise the least amount of Vitamin D; although when sliced have been demonstrated to be proficient D producers. Try this for yourselves.Place the mushrooms with the “gills” i.e. upwards and facing the sun to maximise the D production. The mushrooms have been shown to discolour and dry out a little during this process.
For many vegetarians since Mushrooms are a good protein source this makes sense or If you like mushrooms, those that have been exposed to UV you may get more vitamin D,
Use the links to see edible mushrooms that can be found in your local area for free https://wildfoodism.com/2014/10/07/5-easy-to-identify-edible-mushrooms-for-the-beginning-mushroom-hunter/
http://www.wildfooduk.com/mushroom-guides/